How to convert equations to work with Blender and animation nodes?
This is very easy to do, here I'm showing for a simple equation, y = sin(W*x), where W is a parameter and x is an independent variable.

Step-1
Create two lists, one for the parameter (parameter-1 is as W in this case), and other for variable x. Make a loop using the parameter-1 list as iterator and x-values as an input list,


Step-2
Make a group node (Equation) for y = sin(W*x) equation which later helps you to easily replace with another equation if you want. I'm converting x and resultant y list into a vector list and as output from the group node.


Step-3 
Then add this group node into the Parameter Loop which we created in the step-1, and you view the output vector with 3D viewer Node.


Step-4
Last step to convert group node vectors to splines (curves) using "Splines Form Points" node and then as output from the parameter loop. Use the Curve Object Output node to convert splines to a curve object which you can render.